Tissue Angiotensin and Pathobiology of Vascular Disease

TLDR

Vascular disease involves direct pathobiological events in the vessel wall, where oxidative stress, inflammation, and endothelial dysfunction are driven by a positive‑feedback loop of angiotensin II, reactive oxygen species, and cytokine release, leading to vasoconstriction, thrombosis, and remodeling. The authors aim to develop a model that integrates cardiovascular risk factors, angiotensin II, and related pathobiological mechanisms to explain cardiovascular disease progression. They propose a unified mechanistic model linking risk factors, angiotensin II signaling, oxidative stress, inflammation, and vascular remodeling, which may account for the benefits of ACE inhibitors beyond blood‑pressure lowering.

Abstract

Abstract —There is increasing evidence that direct pathobiological events in the vessel wall play an important role in vascular disease. An important mechanism involves the perturbation of the homeostatic balance between NO and reactive oxygen species. Increased reactive oxygen species can inactivate NO and produce peroxynitrite. Angiotensin II is a potent mediator of oxidative stress and stimulates the release of cytokines and the expression of leukocyte adhesion molecules that mediate vessel wall inflammation. Inflammatory cells release enzymes (including ACE) that generate angiotensin II. Thus, a local positive-feedback mechanism could be established in the vessel wall for oxidative stress, inflammation, and endothelial dysfunction. Angiotensin II also acts as a direct growth factor for vascular smooth muscle cells and can stimulate the local production of metalloproteinases and plasminogen activator inhibitor. Taken together, angiotensin II can promote vasoconstriction, inflammation, thrombosis, and vascular remodeling. In this article, we propose a model that unifies the interrelationship among cardiovascular risk factors, angiotensin II, and the pathobiological mechanisms contributing to cardiovascular disease. This model may also explain the beneficial effects of ACE inhibitors on cardiovascular events beyond blood pressure reduction.